In Bootstrap 3.x, add a class “in” to your collapsable div
<div id="collapse1" class="panel-collapse collapse in">
It will keep your div open by default.
Update:
With Bootstrap 4.0, You need to add show class in place of in.
In Bootstrap 3.x, add a class “in” to your collapsable div
<div id="collapse1" class="panel-collapse collapse in">
It will keep your div open by default.
Update:
With Bootstrap 4.0, You need to add show class in place of in.